Title: Using the Internet to Improve Patient's Self-Management of Chronic Illness Background: Telemedicine has been defined as the use of electronic information and communication technologies to provide and support health care when distance separates the participants. Multiple Sclerosis produces disabilities and care needs that make it an excellent model for studying care delivery improvements, including Telehealth interventions for persons with a broad range of chronic disabilities. The demographics of patients with MS make it generalizable to other chronic conditions and the general population. We have conducted a pilot system of secure electronic messaging system with our patients that is the basis for this research. Objective: Design and test software, designated Mellen Center Care On-Line (MCCO) that includes; an secure electronic messaging system subjects and their MS specialists; a means to guide subjects monitor and manage their illness; a method to assist subjects to prepare for in-person health care visits by helping them to identify major concerns and questions for the appointment. Methods: Conduct a pre-test of MCCO to evaluate the clarity, ease of use and acceptability of the content and presentation of MCCO. Conduct a randomized trial comparing the comprehensive MCCO system with the MCCO secure electronic messaging only system (MCCO-SEMO) which is comparable to our current care. Subjects will be followed for a minimum of 1 year. Study outcomes are health status, self-efficacy for managing MS, satisfaction with care and cost effectiveness. Significance: This proposed research will make a unique contribution by comparing two types of telemedicine interventions. The study design will include assessment of many levels of impact, including health status, enhanced self-efficacy for MS management, satisfaction with health care and cost effectiveness. The design will allow us to assess the impact of patients' physical and cognitive impairment on system utilization. The utilization analysis will allow us to identify the incremental benefit of the comprehensive system compared to the secure system and to determine where there greatest savings in overall cost of care is gained.